1. Field of the Invention
The invention relates to an inked ribbon cassette, in particular for line printers, including a base plate, at least one inked ribbon storage and a guide for the inked ribbon, wherein the inked ribbon storage is furnished by a supply reel.
2. Brief Description of the Background of the Invention Including Prior Art
Such inked ribbon cassettes serve for storing an as large as possible volume of inked ribbon, in order to achieve a production as large as possible of printed pages with a printer of a serial construction and of a line construction. The storing of a large volume of inked ribbon corresponds also to the desires of the user, namely to perform a change of the inked ribbon cassette as rarely as possible. In addition, the change of the inked ribbon cassette is not always associated with the expected knowledge that a person of ordinary skill endeavors to limit the change to the most necessary handling steps by the operating personnel.
On the other hand, the printing rate of the printers such as, for example, of the matrix printers increases continuously in the course of time such that in the course of the development of the printers, the inked ribbon cassette was originally transported together with the print head on the print head slider and, later, there was created a spatially fixed inked ribbon cassette, where the inked ribbon storage is correspondingly larger. However, the volume of the inked ribbon storage cannot be increased arbitrarily because the space required for such volume of inked ribbon is not available in the printing apparatus and, on the other hand, handling the contents of such inked ribbon cassettes becomes more and more difficult.
The discharging and sanitary disposition of the inked ribbon cassettes represents a particular problem. No functioning system exists at this time which allows to dispose of inked ribbon cassettes in an effective manner, as well as of their contents, i.e., the inked ribbon, where the inked ribbon cassettes have been produced with injection molding tools from plastic. It is to be considered in this context that individual inked-ribbon-cassette producers produce daily 500,000 inked ribbon cassettes of all kinds and all dimensions, which are delivered after filling with the inked ribbon to dealers or, respectively, end consumers. In general, it is assumed that the operator of a printer requires annually from about 6 to 7 inked ribbon cassettes. Thus, each printer uses 6 to 7 inked ribbon cassettes annually, which have to be disposed of in an environmentally sound manner. It has now been shown that such a waste disposal could only be performed to the effect that the used inked ribbon is removed from the respective inked ribbon cassette and that the casing of the inked ribbon cassette is melted down again and that inked ribbon cassettes are produced again by the manufacturer. However, it cannot be assumed that such a system would exist or would even properly function and operate. First, already the waste disposal of the inked ribbon from the inked ribbon cassette casing is an economic problem. Then, the return of the inked ribbon cassette casing would also be an economic problem and the reprocessing, i.e., the melting down and the comminution and the re-supply at the producer plant would present an economic and technical problem. Thus, one has to assume after comprehensive considerations that such a recycling system cannot be employed effectively.
Such inked ribbon cassettes are, for example, known from the German Petit Patent DE-GBM 84 08 998.0. This conventional item includes a tensioning device for an inked ribbon disposed in a cassette. The conventional construction is therefore coinciding with the above-recited kind because a supply reel is employed as an inked ribbon storage. It is known to employ a hollow cylinder, rotatable under tension in the cassette casing, as hub of a reel of the supply reel, where the hollow cylinder is slipped over a pin attached to the cassette. A drag spring is disposed between the pin and the hollow cylinder in order to exert a corresponding tension onto the inked ribbon or, respectively, in order to avoid a slacking of the inked ribbon. Such a construction is however not useful, neither with respect to the requirements for a high-power and high-performance printer nor with respect to the problems associated with the disposal of the used product.